This invention relates to a signal recording and reproducing apparatus, and more particularly to an improvement of a video tape recorder.
In a conventional video tape recorder, recording on a control track CTL is performed in the longitudinal direction along the lower edge of the magnetic tape during the recording process on the recording tracks TR. A magnetic head is matched in position with the recording tracks TR on the basis of reproducing signals from the control tracks CTL during the reproducing process of the magnetic tape (FIG. 1).
The control head employed for recording on the control track CTL is provided within a running path of the magnetic tape separately from a rotary drum.
To be specific, as illustrated in FIG. 2, a video tape recorder 1 includes a drum unit 2. A magnetic tape 3 wound on the drum unit 2 is carried from a feed pins 4A, 4B to a control head 6 sequentially through the drum unit 2 and take-up pins 5A, 5B.
The drum unit 2 is now mounted with magnetic heads 7A, 7B disposed at an angular interval of 180.degree.. The drum unit 2 includes an upper drum 2A rotationally driven and a fixed lower drum 2B.
The magnetic heads 7A, 7B sequentially form the recording tracks TR1, TR2 . . . on the magnetic tape 3 wound obliquely on the drum unit 2.
The control head 6 effects recording on the control track CTL along the lower edge of the magnetic tape 3 at a record starting timing of the recording tracks TR1, TR2 . . . in the longitudinal direction.
The above-mentioned control head 6 is, however, positioned outwardly of the take-up pins 5A, 5B with respect to the drum unit 2. Provided is a recording position distance d in the longitudinal direction between the control signal recorded by the control head 6 and a reproduction starting point P of the corresponding recording track TR.
However, if the magnetic tape is stretched or contracted due to temperature characteristics thereof, or if there is a mechanical deviation of the video tape recorder, the positional relation between the recording track TR and the control signal, i.e., the recording position distance d is fluctuated.
This presents a problem of causing an error in the tracking information of the magnetic heads 7A, 7B with respect to the recording track which is now being reproduced by the video tape recorder 1.
The control head 6 is a magnetic head serving for the recording or reproducing process. It is therefore impossible to confirm a state of the control signal to be recorded on the control track CTL during the record on the control track CTL. In some cases, it is not found out that no control track CTL is formed until the magnetic tape 3 is reproduced.